Unable to deauthorize machines I can't see
I'm trying to turn on Home Sharing on my MacBook and it tells me I can't as the maximum number of machines have already been Authorized (5).
Following the instructions I get a little more info:
But then when following the de-authorization instructions, I get this and no option to de-authorize:
I have 1 other 'computer' tied to my iTunes account, an old MacBook that I still use. I have 2 iPads a phone and a watch but I believe these don't count to the quota. Regardless I have no way to de-authorize any of them them anyway...
Any ideas?
MacBook Pro (M1, 2020)